Multiple Glazed Unit

Abstract

A hermetically sealed multiple glazed window unit containing an air space dehydrator element comprising a desiccant material dispersed in a matrix of moisture vapor transmittable material.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 42,712, filed June 2, 1970, now abandoned, which latter application is a continuation-in-part of abandoned application Ser. No. 749,758, filed Aug. 2, 1968 by George H. Bowser, for Multiple Glazed Unit.

Description

BACKGROUND OF THE INVENTION

This invention relates to a novel dehydrator element and, more specifically, to a dehydrator element comprising an admixture of a desiccant material and a moisture vapor transmittable matrix material. In particular, the present invention relates to a novel air space dehydrator element for use in the construction of hermetically sealed, multiple glazed window units.

Multiple glazed units generally comprise two or more sheets of glass spaced from one another to provide an insulating air space between the sheets. This air space is effective for reducing the passage of heat through the unit due to conduction and convection. In one typical form of multiple glazed window construction, the sheets of glass are spaced from each other by a metal marginal edge spacer element extending around the periphery of the glass sheets. The glass sheets are generally adhered to the spacer element by a mastic composition forming a continuous film around the marginal edges of the sheets, between each sheet and the spacer element, to provide a primary hermetic seal. The spacer element is generally tubular in shape and filled with a desiccant. Openings in the spacer element communicate between the air space of the unit and the inside tubular portion of the element so that moisture from the air within the unit will be adsorbed by the desiccant. A resilient, moisture-resistant strip with a layer of mastic adhered thereto is preferably placed around the peripheral edges of the glass sheets and the spacer element to provide a secondary hermetic seal. A channel member of substantially U-shaped cross-section is also preferably affixed around the periphery of the unit to protect the peripheral edges of the glass sheets forming the unit.

One conventional method of assembling multiple glazed units, as above described, is to apply the layer or bead of mastic that forms the primary hermetic seal along two opposite sides of the metal spacer element, which sides are adapted to engage the inner facing surfaces of the glass sheets about their marginal edges. The spacer element is then placed between two pre-cut glass sheets, and the sheets are pressed together to adhere the sheets to the spacer element and to seal the internal air space between the sheets from the atmosphere. The final air space between the two glass sheets is a function of the thickness of the spacer element and the thickness of the mastic layers between each side of the spacer element and the adjacent glass sheet.

A layer of mastic or a resilient, moisture-resistant strip with a layer of mastic adhered thereto is then placed around the peripheral edges of the glass sheets and the spacer element to form the secondary hermetic seal. A channel member made of metal, such as stainless steel, is thereafter affixed around the periphery of the unit. The angle that the flanges or sides of the channel member form with the central or web portion of the channel member is slightly less than 90.degree.. When the channel member is affixed to the edges of the glass sheets, these sides are held apart to allow the glass to be inserted therebetween. These sides are then released and they spring back into contact with the faces of the glass sheets. The channel member is thus held on under tension. The foregoing and other similar types of multiple glazed window construction are fully disclosed in U. S. Pat. Nos. 2,838,810, 2,964,809 and 3,280,523.

A number of vexing manufacturing problems are encountered in producing multiple glazed units of the general type of construction hereinabove described. Principal among these problems is the inherent difficulty of adapting this type of construction to the production of units having non-linear or curved peripheral edge portions. In this regard, a multiple glazed unit can generally be characterized as being either a standard unit, on one hand, or a "pattern" or non-standard unit on the other. A standard unit, as the term is used herein, is simply a flat, rectangular, stock-size unit. Pattern or non-standard units, on the other hand, encompass all of the possible variations from standard, flat, rectangular stock-size units, and include, but are not limited to, non-planar units, non-rectangular units and units provided with one or more curved peripheral edge portions.

Generally, in the manufacture of both standard and pattern multiple glazed units of the type described, a plurality of sections of metallic tubular spacer material are filled with a desiccant and are adjoined at their ends to conform to the perimetrical shape of the unit being produced. In producing a standard multiple glazed unit, four straight sections of tubular spacer material are used and are adjoined at right angles at their ends to form a substantially flat, rectangular spacer element of the desired stock size. In fabricating a pattern multiple glazed unit, on the other hand, the unit design, and accordingly the spacer element, is not restricted to stock size or to a substantially flat, rectangular shape. Thus, sections of tubular spacer material may be joined at an angle other than 90 degrees and/or one or more tubular spacer sections may be pattern-bent or otherwise shaped to conform to the perimetrical contour of pattern-cut and/or pattern-bent glass sheets forming a part of the pattern unit.

It will be apparent from the foregoing that the construction of pattern multiple glazed units greatly increases the normal problems encountered in multiple glazed window construction of the type described. Special jigs and fixtures are frequently required; special handling is required; and units having curved peripheral edge portions require bending the metallic tubular spacer element to conform to the desired contour of the unit. When a concave or convex unit is desired, it is essential that the bent spacer element have a radius of curvature matching that of the glass sheets to ensure uniform thickness of the unit, a good hermetic seal, and to preclude the possibility of imparting any undesired stresses to the glass sheets. Thus, it will be apparent that there is a need for a marginal edge spacer that can be readily used to produce standard, flat, rectangular, stock-size multiple glazed units and that can also be readily bent, shaped, joined or otherwise conformed to any desired perimetrical contour for pattern multiple glazed units. The dehydrator element of the present invention may be used to provide, or serve as part of, just such a spacer.

These and other objects, features and advantages of the present invention will become more apparent from that which follows when taken in conjunction with the drawings, in which:

FIG. 1 is a perspective view of a multiple glazed unit embodying the principles of this invention;

FIG. 2 is a fragmentary view, partly in section, along the line II--II of FIG. 1;

FIG. 3 is a fragmentary sectional view similar to FIG. 2, showing details of one preferred embodiment of this invention;

FIG. 4 is a fragmentary sectional view similar to FIG. 2, showing details of a second preferred embodiment of this invention;

FIG. 5 is a fragmentary sectional view similar to FIG. 2, showing details of a third preferred embodiment of this invention;

FIG. 6 is a fragmetnary sectional view similar to FIG. 2, showing details of a fourth preferred embodiment of this invention;

FIG. 7 is a fragmentary sectional view similar to FIG. 2, showing details of a fifth preferred embodiment of this invention;

FIG. 8 is a fragmentary sectional view similar to FIG. 2, showing details of a sixth preferred embodiment of this invention;

FIG. 9 is a fragmentary sectional view similar to FIG. 2, showing details of a seventh preferred embodiment of this invention;

FIGS. 10 and 11 are fragmentary sectional views of a preferred acoustical multiple glazed unit construction of this invention;

FIG. 12 is a fragmentary sectional view of a modified acoustical unit construction; and

FIG. 13 is a fragmentary sectional view of a further modified acoustical unit construction.

In the drawings, and with particular reference to FIGS. 1 and 2, there is shown a typical pattern, multiple glazed unit 10 comprised of two bent sheets of glass 12 and 14 arranged in parallel relationship and spaced from one another to provide an insulating air space between the sheets. The glass sheets 12 and 14 may be tempered, colored, laminated, or have other special strength or optical properties. As shown, multiple glazed unit 10 is convex in shape and has a curved upper edge 16, a curved lower edge 18 and straight side edges 20 and 22.

As best shown in FIG. 2, the glass sheets 12 and 14 are separated at their marginal edges by a continuous dehydrator element 24, which in this case also serves as part of the entire spacer element. The dehydrator element 24 has an essentially dog-bone cross-sectional shape and is adhered to the glass sheets 12 and 14 at their interfaces by means of a continuous film or bead of an adhesive, moisture-resistant, mastic composition 26. In addition, a bead or layer of moisture-resistant, mastic composition 28 is adhered or bonded to the peripheral edge of dehydrator element 24, the peripheral edges 30 of the glass sheets and marginal edge portions 32 of the outer faces of the glass sheets. Mastic compositions 26 and 28 extend completely around the perimeter of the unit and may be composed of the same material or dissimilar materials. A channel member 34 of essentially U-shaped cross-section also extends completely around the perimeter of the unit to protect its edges. Channel member 34 is generally composed of several sections of channeling that are joined or butted together at their ends. Where desired, a strip of adhesive tape (not shown) may be applied in longitudinal, surrounding relation with the outer surfaces of channel member 34. A preferred construction and method of attachment for channel member 34, for use with certain pattern units, are fully disclosed in application Ser. No. 706,896, filed Feb. 20, 1968, now U.S. Pat. No. 3,540,118 by T. H. Hughes, and assigned to the assignee of the present invention.

Dehydrator element 24 forms the basis for the present invention. Dehydrator element 24 is composed of a desiccant material 36 dispersed in a moisture vapor transmittable matrix material 38. In accordance with this invention, the moisture vapor transmittable matrix material 38 functions to provide the required communication between the air space of the unit 10 and the desiccant material 36, so that moisture from the air within the unit will be adsorbed by the substantially uniformly dispersed desiccant. In addition to being a moisture vapor transmittable material, matrix material 38 is preferably also a material that is flexible or readily conformable at room temperature to any shape or contour that may be desired.

The preferred type or class of desiccant materials that may be used in the practice of this invention, and which are now covered by composition of matter patents, are the synthetically produced crystalline metal aluminosilicates or crystalline zeolites. A specific example of a synthetically produced crystalline zeolite that is particularly satisfactory and which is covered by U. S. Pat. Nos. 2,882,243 and 2,882,244 is Linde Molecular Sieve 13X, in powdered form, produced by Union Carbide Corporation. However, other desiccant or adsorbent materials, preferably in pulverulent form or which disintegrate into pulverulent form when dispersed in the matrix, may also be used, such as anhydrous calcium sulfate, activated alumina, silica gel and the like.

The preferred type or class of matrix materials or moisture vapor transmittable materials that may be employed in connection with this invention are the family of thermoplastic elastomers comprising block copolymers of styrene and butadiene, such as are now disclosed in U. S. Pat. No. 3,265,765. A specific example of a particularly suitable thermoplastic block copolymer of styrene and butadiene is Thermolastic 226 produced by Shell Chemical Company. However, other thermoplastic moisture vapor transmittable materials, as well as moisture vapor transmittable thermosetting materials and vulcanizable materials, may also be used.

In accordance with the present invention, it is only essential that the particular matrix material being used is capable of transmitting moisture vapor and is also capable of functioning as a matrix material for the particular desiccant employed. In order that adsorption by a desiccant dispersed therein can proceed at a reasonable rate, the moisture vapor transmittable material selected should desirably have a substantial water vapor transmission which for most purposes should be above about 15 gm./24 hr./1 sq. meter/mil at 100.degree.F., 90% R.H., as determined by the Standard Methods of Test for Water Vapor Transmission of Materials in Sheet Form, ASTM Designation E-96-66 Method E. Preferably, however, the water vapor transmission of the matrix material used should be above about 40 gm./24 hr./1 sq. meter/mil at 100.degree.F., 90% R.H. Particularly good results are achieved when the water vapor transmission of the matrix material selected is above about 50 gm./24 hr./ 1 sq. meter/mil at 100.degree.F., 90% R.H. The water vapor transmission of Thermolastic 226 is about 55 gm./24 hr./1 sq. meter/mil at 100.degree.F., 90% R.H.

Examples of materials in addition to Thermolastic 226 having the foregoing desired characteristics include: polyacrylate elastomers, conjugated diene polymers and copolymers such as natural rubber, polybutadiene, polyisoprene, acrylonitrile-butadiene copolymers, polybutadiene elastomers, silicone elastomers, urethane elastomers, as well as epoxy resins, polyester resins, polyamide resins, phenolic resins, urea-formaldehyde resins, cellulose acetate resins, polycarbonate resins, polystyrene resins, polyvinyl alcohol resins, vinyl chloride-vinyl acetate copolymers, ethylenevinyl acetate copolymers and the like or other materials, particularly resinous materials which provide a continuous phase, preferably flexible in character, in which the desiccant may be dispersed and which are themselves water permeable to an appreciable degree. The matrix may be vulcanizable or unvulcanizable, and if vulcanizable may be used and stored for use in the vulcanized or unvulcanized state. Vulcanizing or curing agents may be introduced if desired, but preferably they are omitted.

EXAMPLE I

In accordance with the present invention, a dehydrator element 24 was prepared in the following manner and having the following composition:

INGREDIENT Parts by weight Thermolastic 226 100 Linde Molecular Sieve 13.times. 50 Carbon black (Statex G) 5

pellets of the Thermolastic 226 were added to a two-roll mill heated to a temperature of about 250.degree.F. The pellets were allowed to soak approximately 5 minutes before the mill was turned on. The pellets were then thoroughly milled until a uniform sheet of the material was formed. Powdered Linde Molecular Sieve 13X was added slowly to the sheet of Thermolastic 226 and, after the addition of all of the molecular sieve material, the resultant sheet was stripped and returned to the mill at least 5 times. This process of addition of material, stripping and returning to the mill was then repeated with the addition of the carbon black. Carbon black is used merely as an opacifying agent and its use is not essential to this invention. The completed composition was removed from the mill and cut into 1/2-inch strips which were stored in a sealed container in preparation for subsequent extrusion to the desired shape.

A die was selected to provide the desired shape for the dehydrator element. This die was placed in a Killion 100 extruder. The barrel of the extruder was heated to approximately 250.degree.F. and the die was heated to approximately 240.degree. to 260.degree.F. The extruder screw speed setting was approximately 2.5. The previously prepared 1/2-inch strips of material having the desired composition for the dehydrator element were then added to the feed hopper and extruded to the desired shape.

The following are typical properties of Thermolastic 226 and Linde Molecular Sieve 13X:

thermolastic 226

low temperature flexibility .degree.F. to Young's modulus of 10,000 psi. -55 Tensile strength.sup.a at break, psi. 650 Modulus.sup.a at 300% extension, psi. 275 Elongation.sup.a at break, % 740 Set.sup.a at break, % 15 Elongation/set 50 Hardness, Shore A 45 Yerzley resilience,.sup.b % 78 Falling ball rebound, % 65 Specific gravity.sup.c 1.00 Melt index.sup.d g/10 min. G 90 E 20 .sup.a "D" die specimen extended at 200%/min., 23.degree.C. .sup.b At 20% deflection, 23.degree.C. .sup.c Measured using air pycnometer, 23.degree.C. .sup.d ASTM D-1238

LINDE MOLECULAR SIEVE 13.times.

Heat of Equili- Nominal Bulk Adsorp- brium Pore density tion H.sub.2 O Mole- diameter (lb./ (max.) capacity cules (A.) Form cu.ft.) (btu/lb. (% Wt.)* adsorbed H.sub.2 O) 10 Powder 30 1800 36 Molecules with an effective diameter <10 angstroms * Lbs. H.sub.2 O/100 lbs. activated adsorbent at 17.5 mm Hg. 25.degree.C.

moisture adsorption tests run on the powdered Linde Molecular Sieve 13X, as received, and the dehydrator element of Example I showed that, at 140.degree.F. and 96 percent relative humidity, the desiccant in both samples adsorbed approximately the same per cent moisture, i.e., 27.2 percent by weight based on the weight of desiccant.

TABLE 1

WATER ADSORPTION TEST

Percent Increase in Moisture Dehydrator 19 hours 142 hours 15 days Powdered Linde Molecular Sieve 13.times. (as received) 27.02 27.24 27.26 Composition of Example I 13.81 23.28 27.18

as will be noted, the dehydrator element required approximately 15 days to saturate the desiccant while the powdered material, as received, became essentially saturated within 24 hours. From the foregoing, it has been calculated that no more than 0.3 percent by weight of Linde Molecular Sieve 13X, based on the weight of the ingredients of Example I, is required to obtain a dew point of 0.degree.F. in a multiple glazed unit fabricated at 70.degree.F., 90% R.H. and measuring 14 inches by 20 inches with the glass sheets spaced 1/4-inch apart by a 1/4-inch x 5/16-inch dehydrator of Example I extending completely around the periphery of the unit. Furthermore, by increasing the parts by weight of powdered Linde Molecular Sieve 13X added to the Thermolastic 226 ingredient of Example I, it has been determined that at least as much as 60 percent by weight of desiccant based on the total weight of the ingredients can be dispersed in Thermolastic 226.

Adhesive, moisture-resistant, e.g., air impermeable, mastic compositions 26,28 that have been successfully used in the practice of this invention include pre-cured materials, such as disclosed in U. S. Pat. No. 2,974,377, thermoplastic materials, such as disclosed in Handbook of Adhesives, Chapter 36, entitled "Hot-Melt Adhesives," Reinhold Publishing Corp., 1962, and room temperature curable materials, such as disclosed in U. S. Pat. No. 3,076,777. Room temperature curable materials that cold flow to form a seal and cure to form a resilient structural bond are particularly desirable for use with this invention.

Shown in FIGS. 3 through 13 are a number of specific, alternative embodiments of the present invention. The construction of FIG. 3 differs, for example, from the construction of FIG. 2 in that, in lieu of providing a bead or layer of mastic 28 around the periphery and marginal edge portions of the unit as described in connection with FIG. 2, a resilient, moisture-resistant, plastic strip 40 with a layer of mastic 28 adhered thereto is placed around the peripheral edges of the glass sheets 12 and 14 and the dehydrator element 24. A channel member 34 is thereafter affixed around the periphery of the unit.

In the construction of FIG. 4, like that of FIGS. 2 and 3, dehydrator element 24 is adhered by mastic 26 to the marginal edges of the glass sheets 12 and 14. A strip of aluminum foil 42 with a layer of mastic 28 adhered thereto is placed around the peripheral edges of the glass sheets 12 and 14 and the dehydrator element 24, as well as around marginal edge portions 32 of the outer facing surfaces of the glass sheets.

In the construction of FIG. 5, in lieu of using aluminum foil, such as shown in FIG. 4, a pressure-sensitive strip 44 with a layer of mastic 28 adhered thereto is placed around the peripheral edges of the glass sheets 12 and 14 and the dehydrator element 24. As shown, mastic 28 terminates at the outer facing surface of each of the glass sheets and the pressure-sensitive strip 44, which is wider than the thickness of the finished unit 10, is turned down and adhered to marginal edge portions 32 of these outer facing glass sheet surfaces.

Shown in FIG. 6 is another alternative embodiment of this invention wherein a strip of aluminum foil 42 is provided with a layer of mastic 28 and a rectangular dehydrator element 24 is either extruded directly onto or, after formation, is placed onto the mastic material 28. The dehydrator element readily adheres to the mastic 28. The sides of dehydrator element 24 are primed with a thin coating of a rubber-base adhesive 46 and dehydrator element 24 is then placed between opposed marginal edges of a pair of glass sheets 12 and 14. The lateral edges of the foil strip are adhered by the mastic layer 28 around marginal edge portions 32 of the outer facing surfaces of the glass sheets.

In FIG. 7 there is shown a further alternative embodiment of this invention. In the embodiment of FIG. 7, a mastic, spacer-sealant element 48, of the same or similar composition as mastic 26 or mastic 28 of previous embodiments, is disposed between opposed marginal edges of the inner facing surfaces of the glass sheets 12 and 14 and carries an insert of dehydrator material 24. This insert 24 is in communication with the air space between the glass sheets. A strip of metal foil or plastic sheeting 50 having a pressure-sensitive coating is disposed around the peripheral edges of the glass sheets and the mastic, spacer-sealant element 48.

The embodiment of FIG. 8 is similar to that of FIG. 7 except that in this embodiment a triangular insert of dehydrator material 24 rather than a rectangular insert is used. Also, spacer-sealant element 48 is T-shaped and the arms of the tee extend across the peripheral edges of the glass sheets in the manner of mastic 28 of previous embodiments. Furthermore, in this embodiment the strip of metal foil or plastic sheeting 50 is not provided with a pressure-sensitive coating, since either the metal foil or the plastic sheeting will readily adhere to the mastic material of which spacer-sealant element 48 is composed.

Shown in FIG. 9 is a still further embodiment of this invention. In this embodiment, the dehydrator element 24 is essentially T-shaped in cross-section. As Shown, dehydrator element 24 has a retangular leg portion 52 which is disposed between opposed marginal edges of a pair of glass sheets 12 and 14 to space the sheets apart. The sides of dehydrator element 24 are primed with a thin coating of a rubber-base adhesive 46. Each arm 54 of this member is disposed in contact with and extends for a short distance across an adjacent peripheral edge portion of one of the glass sheets. As will be apparent, arms 54 provide reference ledges for properly locating element 24 with respect to the glass sheets. Also, arms 54 resist or preclude the possibility of inserting or forcing any portion of element 24 inwardly of the peripheral edge of the unit 10 further than iS desired. As in FIG. 2, a layer or bead of moisture-resistant mastic 28 and a channel member 34 each extend around the perimeter of the unit to complete its structure.

Illustrated in FIGS. 10 to 13 are acoustical multiple glazed unit constructionS that advantageously employ the dehydrator element 24 of this invention in their structures. Shown in FIGS. 10 and 11 is a preferred acoustical multiple glazed unit construction in which glass sheets 12 and 14 are Of unequal thickness to achieve a mismatch of their resonent frequencies, hence better reduction of sound transmission through the unit. Also, glass sheets 12 and 14 are spaced apart to provide an air space therebetween of about 1 inch or greater, preferably from about 2 to about 4 inches, to enhance sound transmission loss through the unit. The marginal edge portions of the glass sheets are rigidly supported at the desired spaced apart distance by a perimeter spacer channel 56 adhered by a layer or bead of moisture-resistant mastic 26 to the air space marginal edge portions of both glass sheets.

Spacer channel 56 is preferably composed of aluminum or galvanized steel and, in the embodiment shown, has an essentially U-shaped cross-section. As shown, the web 58 of spacer channel 56 is disposed adjacent the perimeter of the unit and the flanges or legs 60 of the U-channel extend inwardly of the unit therefrom. Flanges 60 are preferably L-shaped and their free ends are disposed in opposed, spaced relation to each other. Inserted within spacer channel 56 and extending therewith completely around the unit is dehydrator element 24 of the composition of Example I. Dehydrator element 24 may have a rectangular corss-section corresponding to the rectangular space embraced by spacer channel 56 or, as shown, may have a suitably modified cross-section to permit bending element 24 to facilitate its insertion into spacer channel 56. A layer of bead of moisture-resistant mastic 28 and a channel member 34 each extend around the perimeter of the unit, in the manner described above in connection with FIGS. 1 and 2, to complete its structure.

Shown in FIGS. 12 and 13 are modified acoustical unit constructions. In the embodiment of FIG. 12, the edge channeling 34 of the FIGS. 10 and 11 construction is eliminated and a pressure-sensitive plastic strip or metal foil 44 is used to enclose the peripheral edges of the unit as described above in connection with FIG. 5. In the embodiment of FIG. 13, the construction shown in FIG. 12 is further modified by eliminating spacer channel 56 and adhering dehydrator element 24 directly to the marginal edge portions of the air space surfaces of the glass sheets 12 and 14 with mastic 26. The acoustical performance of units constructed in accordance with FIGS. 10 to 13 is recorded hereinafter.

In accordance with this invention, rectangular test specimens were constructed measuring 14 inches by 20 inches and comprised of two sheets of 1/8-inch glass separated by an air space of 1/4-inch .+-. 3/32 inch. Each specimen had an initial dew point of -60.degree.F. or lower. The following tests were conducted with the results being indicated in each case.

HIGH HUMIDITY TEST

Test specimens were exposed for a continuous 60-day period to ambient atmospheric conditions maintained at 110.degree.F. and 90 percent relative humidity. A specimen was considered to pass this test if, at the end of the 60-day exposure period, the dew point of the specimen was -60.degree.F. or lower.

Unit Unit Dew Point, .degree.F. Design No. Initial 30 days 60 days Remarks FIG. 6 1 -60 -60 -60 Passed Test FIG. 6 2 -60 -60 -60 Passed Test FIG. 6 3 -60 -60 -60 Passed Test FIG. 6 4 -60 -60 -54 Acceptable

TEMPERATURE CYCLING AND HIGH HUMIDITY TEST

Test specimens were exposed to an ambient atmosphere maintained at 90 percent relative humidity and were gradually heated to 120.degree.F. .+-. 5, during a 3-hour period, followed immediately by gradual cooling to 20.degree.F. .+-. 5, during a 3-hour period. A specimen was considered to pass the test if, after at least 300 cycles, the dew point of the specimen was -60.degree.F. or lower. ##SPC1##

ULTRAVIOLET EXPOSURE AND CYCLING

Test specimens were exposed for a continuous period of 500 hours to ultraviolet radiation. Glass temperature, as measured at corner surface areas of the specimens, was controlled so as to not to exceed 120.degree.F. A specimen was considered to pass the ultraviolet exposure phase of this test if, after 500 hours, the dew point of the specimen was -60.degree.F. or lower.

Immediately upon completion of the ultraviolet exposure phase of this test, the specimens were exposed to the above-described Temperature Cycling and High Humidity Test for a period of 60 continuous cycles. A specimen was considered to pass the complete test if, after 60 cycles of the Temperature Cycling and High Humidity Test, the dew point of the specimen was -60.degree.F. or lower. ##SPC2##

ACOUSTICAL TESTING

Rectangular units measuring 35-3/4 .times. 83-3/4 inches were constructed in the manner shown in FIGS. 10 to 13 and tested to determine their Sound Transmission Class (STC) in accordance with ASTM Designation E90-66T and RM 14-2 testing procedure. The results of these tests are recorded below:

Unit Geometry Unit Construction STC* 1/4" glass -- 2" air space -- 1/4" glass FIGS. 10 and 11 38 1/4' glass - 2" air space -- 3/8' glass FIGS. 10 and 11 39 1/4" glass -- 2" air space -- 1/4" glass FIG. 12 40 1/4" glass - 2" air space -- 3/16" glass FIG. 12 44 1/4" glass -- 2" air space -- 1/4" glass FIG. 13 40 1/4" glass -- 1" air space-- 3/16" glass FIG. 13 38 * Sound Transmission Class

The composition of the dehydrator element, employed as a marginal edge spacer component in the foregoing tests, was that of Example I. As mentioned previously, this composition produces a dehydrator element having elastomeric properties. The use of an elastomeric or flexible dehydrator element is considered to be particularly desirable in the furtherance of this invention because it can be readily used to produce a marginal edge spacer for standard multiple glazed units and can also be readily bent, shaped, notched, joined or otherwise conformed to any desired perimetrical contour for use in the construction of pattern and acoustical multiple glazed units. As the test results indicate, multiple glazed units constructed in accordance with this invention perform extremely well under even the most severe conditions of test.

Desiccant used according to this invention include those stable materials commonly used for this purpose and should generally be construed to include materials capable of picking up from the atmosphere in excess of 5 to 10 percent of its weight, preferably in excess of 10 percent of its weight, in moisture (water).

Although the present invention has been described with particular reference to the specific details of certain embodiments thereof, it is not intended that such details shall be regarded as limitations upon the scope of the invention except insofar as included in the accompanying claims.

Claims

I claim:

1. A multiple glazed unit comprising:

a pair of rigid sheets arranged in generally parallel relation, and having opposing surfaces adjacent peripheral marginal edges of each of said sheets,

a preformed, elastic spacer-dehydrator element disposed between said opposing surfaces of said rigid sheets adjacent the peripheral marginal edges thereof, and adapted to conform to the shape of the space between and defined by said opposing surfaces so as to maintain said rigid sheets in spaced relation,

said preformed elastic spacer-dehydrator element comprising a moisture-transmittable organic elastic polymeric matrix having finely divided particles of a desiccant material dispersed throughout said matrix, and

a layer of a moisture-resistant material overlying said preformed elastic spacer-dehydrator element and extending between the opposing surfaces of said rigid sheets from the peripheral edge of one sheet to the peripheral edge of the other of said sheets to provide a moisture-resistant layer overlying, in circumscribing relation, said spacer-dehydrator element and the space between said rigid sheets.

2. The multiple glazed unit of claim 1 wherein at least one of said rigid sheets is comprised of glass.

3. The multiple glazed unit of claim 1 wherein both of said rigid sheets are comprised of glass.

4. The multiple glazed unit of claim 1 wherein the spacer-dehydrator element comprises separate spacer and dehydrator elements, the dehydrator element comprising said desiccant dispersed in said matrix.

5. The multiple glazed unit of claim 1 wherein the matrix is an elastomer.

6. The multiple glazed unit of claim 1 wherein the matrix is an elastomer and the desiccant is a powder which is dispersed in the elastomer.

7. The multiple glazed unit of claim 1 wherein said moisture vapor transmittable material has a water vapor transmission of above about 15 gm./24 hr./1 sq. meter/mil at 100.degree.F., 90% R.H.

8. The multiple glazed unit of claim 1 wherein said moisture vapor transmittable material has a water vapor transmission of above about 40 gm./24 hr./1 sq. meter/mil at 100.degree.F., 90% R.H.

9. The multiple glazed unit of claim 1 wherein said moisture vapor transmittable material has a water vapor transmission of above about 50 gm./24 hr./1 sq. meter/mil at 100.degree.F., 90% R.H.

10. The multiple glazed unit of claim 1 wherein said moisture vapor transmittable material comprises a flexible material.

11. The multiple glazed unit of claim 1 wherein said desiccant material comprises an adsorbent material.

12. The multiple glazed unit of claim 1 wherein said moisture vapor transmittable material comprises a block copolymer of styrene-butadiene rubber.

13. The multiple glazed unit of claim 11 wherein said adsorbent material comprises a zeolite.

14. The multiple glazed unit of claim 13 wherein said zeolite comprises a crystalline metal aluminosilicate.

15. The multiple glazed unit of claim 14 wherein said moisture vapor transmittable material comprises a block copolymer of styrene-butadiene rubber.

16. The multiple glazed unit of claim 1 wherein said moisture-resistant material is air impermeable.

17. The multiple glazed unit of claim 1 which further includes a moisture-resistant material extending between said opposing surfaces and said spacer-dehydrator element.

18. The multiple glazed unit of claim 1 wherein said moisture-resistant material extends across the adjacent peripheral edges of said rigid sheets.

19. The multiple glazed unit of claim 1 wherein said moisture-resistant material is a thermoplastic material.

20. The multiple glazed unit of claim 1 wherein said moisture-resistant material is a curable material.

21. The multiple glazed unit of claim 1 which further includes a metallic member extending in circumscribing relation about the periphery of said unit.

22. The multiple glazed unit of claim 1 which further includes a synthetic plastic member extending in circumscribing relation about the periphery of said unit.